Listing 1 is very simple but it has all the basic elements of an HTML form with JavaScript. In this case, the JavaScript takes the input value and displays it in an alert popup. Here’s an ...

Form validation is the process of checking whether the data entered by the user in a form matches the expected format, type, range, or other criteria. For example, you might want to validate that ...

TOS is short for Terms of Service. Here, the alert() in the submit event handler should only be called if the tos checkbox has been checked. 💡 You can use an early ...